Arrow Lock, MK12 BD 26D 300 114 KD AR, Satin Chrome 26D, Ball Knobe D Rose, Storeroom Always Locked Vestibule, Grade 2 Commercial Cylindrical Ball Lockset Lock Set, 2-3/4" Backset. Finish: 26D Satin Chrome. Design: BD - Ball Knob D Rose. Strike: 300 - 1-1/8" x 2-3/4", 1-1/4" lip, square corner, no box. Latch: 114 - 2-3/4" Backset 1-1/8", square corner. Keyway: A - Arrow A. Storeroom Set Dead Locking Latch Bolt Operated By Key In Outside Knob Or By Operating Inside Knob. Outside Knob Is Always Inoperable. Arrow MK Series offer the Security Professional simple solutions to accessibility requirements. Their clean designs, architectural finishes and available functions make them ideal for commercial applications where heavy duty grade one hardware may not be necessary. Certification. ANSI/BHMA A156.2, Series 4000, Grade 2. Underwriters Laboratories (UL and CUL) listed for use on 3 hour, A label single swinging doors. Federal Specifications FF-H-106C, Series 160. Lock Chassis: Cold rolled steel with zinc dichromate finish for corrosion resistance. Requires standard 2-1/8" (53.97 mm) bore through door.